ads.txt for Publishers

Identify yourself to buyers as an authorized seller by including an ads.txt file for your video, display, and mobile inventory.

Oath supports the industry-wide ads.txt initiative. We are partnering with both DSP's and supply sources to facilitate the enforcement of ads.txt files by our DSP partners.

Just what is ads.txt?

Ads.txt was created by the IAB to allow publishers to publicly declare the specific exchanges they work within the digital advertising space. The goal of ads.txt is to improve transparency and decrease fraud revenue.

How is the ads.txt file formatted?

The format for ads.txt file is: #< SSP/Exchange Domain >, < SellerAccountID >, < PaymentsType >, < TAGID >

This is an Oath example (note: it does not include the optional TAGID)

#ads.txt file sample
 , 12000, DIRECT #banner, US, 3679, DIRECT #video, US, 20459933223, DIRECT # banner, US, 25980889636, DIRECT # banner, CA, 4577, DIRECT #banner, app

How do I include Oath in my file?

To include Oath in your file, publishers must have at least 3 of the 4 mandatory fields inserted into the .txt file that you host. Each field is separated by a comma and each company has its own line of code.

The domain entered in Field #1 is dependent on the platform you are monetizing:

Platform Domain
ONE by AOL: Mobile
ONE by AOL: Video
ONE by AOL: Display
Display Brightroll from Yahoo!

Publisher IDs (the ID we assigned and you pass in the ad call) are entered into Field #2. If you don’t know your ID, reach out to an Account Manager.

NOTE: Pubs that have been set up in the US, EU and APAC ADTECH systems should include multiple publisher IDs.

Enter the type of relationship in Field #3.

  • Direct
  • Reseller

Field #4 is optional, leave it blank for Oath. We are in the process of getting TAG (Trustworthy Accountability Group) certified.

What happens next?

DSP’s actively crawl the web looking for ads.txt files and the data they contain. Oath’s code appearing in the file confirms that the inventory is held by an authorized seller.

*Please note the ads.txt file information applies to all ONE for AOL platforms, not just ONE for AOL: Mobile.


Ads.txt FAQ’s

Q: What does ADS stand for?

A: Authorized Digital Sellers

Q: Which platforms could be impacted?

A: Ads.txt works on all of our platforms -ONE for AOL: Video, Display, and Mobile (mobile web inventory only, not in-app)- as well as on Brightroll from Yahoo! Ads.txt is working to eliminate counterfeit or spoofed inventory and prevent the reselling of an unauthorized impression. This can impact all resellers on the above-listed supply platforms.

Q: Does a non-authorized seller mean they have invalid traffic?

A: No, not necessarily. It may mean the inventory is being resold without the publisher's knowledge, the partner didn't get added to the ads.txt file in time for publication or was inadvertently left out. It could also mean the publishers decided to not participate.

Q: Can I see a current example of a live ads.txt file?

A: View examples of live ads.txt files at or

Q: What is the Certification Authority ID? And does ONE by AOL have one?

A: A certification Authority ID uniquely identifies the advertising system (this ID maps to the entity listed in field #1). One certification authority is the Trustworthy Accountability Group (aka TAG). The TAGID is optional and would appear in field #4. More info and examples can be found in the IAB OpenRTB ads.txt Spec on pages 6 & 8.

Oath is currently in the process of obtaining the TAG certification, but we are not yet certified. This field is optional and not required in the ads.txt file.

Q: Are ID’s consistent across AOL’s platform?

A: No, ID’s can vary from platform to platform as well as country to country. The Exchange/Seat ID would be the Publisher's Network ID in Marketplace (for ONE by AOL: Display). If the Pub is set up in both US and EU, they must enter two lines in their ads.txt file - one for each Network ID.

Q: I work with you through a Header Tag (via Prebid), can I use the Publisher ID that corresponds to that integration?

A: Yes, the Pub ID is the same.

Q: Does the ONE by AOL exchange offer my inventory on other exchanges on my behalf?

A: Yes, we work with exchanges who are resellers. It is up to the publisher to authorize these resellers on their ads.txt file. We recommend you work with your account manager to make sure you have the correct reseller information.

Q: Can I see a sample crawler for buyers?

A: Yes, please reference the IAB page here.

Q: Do all SSP’s use publisher ID?

A: Most SSP’s use publisher ID; but that depends on the partner’s platform. We recommend you reach out directly to the SSP’s you work with.

Q: What are the lines starting with # symbol?

A: These are considered comments and are ignored by the system.

Q: Do you have a sample bid request for ONE by AOL: Mobile?

A: Yes, see the ONE by AOL: Mobile sample bid request below.

"publisher": {
       "id" : "17382",
       "Name" : "PRO12 Mobile",
       "Ext" : {
       "Nex_else" : 0

Q. Do you have a sample bid request for ONE by AOL: Display where we can see publisher ID?

A: Yes, see the ONE by AOL: Display sample bid request below.

"site": {
     "id": "50-1234",
     "page": "",
     "publisher": {
     "id": "50"

Q: Is Oath actively crawling the web for ads.txt files?

A: Yes, we started crawling in September 2017.

Q: What happens if no ads.txt file is present?

A: DSPs can interpret the absence of ads.txt files in two ways:

  • Assume that no advertising is unauthorized because no file is present
  • Reach out to the publisher to get authorization to sell inventory

Q: What if DSP buyers want to target/exclude based on one or more of these options?

  • Authorized reseller
  • Non-Participating
  • Non-authorized reseller

A: Targeting (including or excluding seller’s inventory) is controlled by the DSP. Once ads.txt becomes widely adopted, we anticipate DSP’s will make bid decisions based on information they find in specific ads.txt files.

Still have questions? Please reach out to your ONE by AOL account manager.

Have more questions? Submit a request